Hydrogels for Bone Regeneration: Properties, Additives, Preclinical and Clinical Applications

Severe bone loss from trauma, fractures, tumor resections, and disease are devastating injuries that do not heal completely without external, and most of the time surgical, interventions. Although surgical interventions such as bone grafts and metal prostheses are commonly employed, these conventional approaches present several limitations, including limited donors, risks of immune rejection and postoperative inflammation, and significant pain experienced by both donors and recipients. Hydrogels offer a promising alternative because of their controllable mechanical properties, biocompatibility, and structural resemblance to the extracellular matrix. In addition, hydrogels can be modified with substances such as growth factors, hormones, and drugs to facilitate accelerated bone repair. This review summarizes the recent advances in hydrogel development for bone repair, their structural design, biological functionality, and preclinical and clinical applications.